Wortmannin is a known potent inhibitor of phosphotidylinositol-3-kinase (PI-3-kinase), and has been suggested for use as a potential anti-cancer agent. Wortmannin is a naturally occurring compound isolated from culture broths of the fungus Penicillium wortmannin and has the following basic structure: ##STR1##
One of the disadvantages of wortmannin is its toxicity to living creatures. Even in low dosages, wortmannin in pure form was often lethal to laboratory animals. Attempts to synthesize derivatives of wortmannin have so far been problematical.